State threatens to fine health insurers

State regulators today demanded that health insurers submit revised April 1 premium rates for tens of thousands of individuals and small businesses by 3 p.m. Thursday or face stiff fines.

The fines could run to as much as $5,000 a day per carrier, plus $1,000 for each consumer who is unable to buy coverage, according to a letter sent by Insurance Commissioner Joseph G. Murphy this afternoon to Massachusetts insurers.